"Killer Joe" is playwright and Tony Award winner Tracy Letts's ("August: Osage County") adaptation of his 1993 play. Directed by William Friedkin ("The Excorcist"), it is a violent nightmare of a ride that takes place deep in Texas's heartland. One cannot escape from the overall Texas vibe of the film. It is very much a cowboy noir. Its star is Matthew McConaughey ("Magic Mike"), who plays the tough-as-nails gunman-for-hire, "Killer Joe" Cooper. He is contracted to kill the mother of small-time drug dealer Chris Smith (Emile Hirsch), so Smith can collect the proceeds from her life insurance policy. However, in this dysfunctional family, the mother is not innocent; she stole the cocaine Chris was supposed to sell.

Smith is what is commonly referred to in a derogatory sense as "white trash," and he is in deep debt-to the tune of $6,000-to a local drug gang. If his plans are not heinous enough, he also talks his dad, Ansel (Thomas Haden Church), into following along with them. It's Ansel's idea to hire Joe to perform the deed. Smith's face is covered in huge purple blotches when he first meets Joe, the result of being beaten to a pulp by his creditor. Because he has no cash, he gives his dimwitted, virgin sister, Dottie (Juno Temple), to Joe as collateral on the deal.

While Tarratino would have made the horrific scenes in the film actually enjoyable, Friedkin's direction makes it disconcerting to the audience. There is nothing redeeming or funny in the sheer soulless actions taken by Killer Joe to meet his contract. There is no context or background given about Joe that could possibly give insight to why he is so vile and heartless. The only information that can be gleaned about him is that he is a cop living a double life as a hit man. At least there is a childhood story about Dottie that gives insight into the Smiths's precarious situation.

McConaughey expertly plays a pretty boy bad guy. Joe is a handsome charmer, and knowing this, he uses it to his advantage. His smile is that of a deceptive, cold-hearted snake. He and the Smiths are truly loathsome and morally bankrupt people. The best movies give their villains a backstory to inform about their violent tendencies. Even Hannibal Lector from "Silence of the Lambs" had a perfectly understandable reason for being psychotic. For many of these characters, there is no possibility for redemption.

As far as the comedy element of the film, most of this stems from the sheer stupidity of the Smith men. These fellows could probably use a refresher course in breathing. The writing is witty and entertaining, plus the cast is capable of determining the best manner to deliver them. There are some lessons to learn from this tale. For one thing, don't ever assume that you're smarter than you really are. The Smiths are outwitted in a huge way, and of course, karma is not kind. You get what's coming to you.

The initial action is immersive and heart-pounding and at times feels very desperate. Excellent lighting, camera work and an appropriate soundtrack add to the dark ambience. The second half of the film takes on another pace, as it mainly takes place in a kitchen. There is a long sex-oriented scene that will probably have audiences looking at chicken drumsticks funny for the rest of their lives. Joe's seduction of Dottie and some full-frontal nudity is why the film was issued the NC-17 rating. By the end of the story, Joe will get what is his, but the goal and reward are very different from the initial contract at the start of the film. It is a nasty and bloody finale, acted in a dramatic manner that is specifically tailored to be memorable.

For those that want the darkest and most unpleasant things that humanity has to offer, this film fits the bill. Sometimes the scariest things are human. Many summer blockbusters rely on huge special effects and CGI, but this down and dirty thriller is just as capable in gripping an audience. Just be sure to hold onto your stomach.